IBM 990 - Manual (Page 225)

Chapter 8. Capacity upgrades 213
Dedicated and shared logical partitions upgrade
Figure 8-12 shows a 2084-B16 software model 309 server. This two-book server
configuration has nine CPs and seven spare PUs.
Figure 8-12 Dedicated and shared logical partitions upgrade example
This 2084-B16 software model 309 (with no ICFs or IFLs) can be concurrently upgraded to
the software model 316 via LIC-CC, with no model upgrade.
There are three activated logical partitions: LP1 has three dedicated (DED) logical CPs and
two reserved CPs defined, LP2 has six shared (SHR) logical CPs and two reserved CPs
defined, and LP3 also has six shared (SHR) logical CPs and two reserved CPS defined.
This example shows an upgrade to the 2084-B16 software model 311, by adding,
concurrently, two more CPs to the physical configuration. Two available spare PUs are used
by LIC-CC for this upgrade. The physical upgrade ends here.
At this point, even with no partition configuration changes, LP2 and LP3 (shared) partitions
may experience performance improvements. As there is now more available capacity
(physical processors) to be used by all logical shared CPs, the “logical-to-physical processors
ratio” is reduced. In this example, before the upgrade, there were twelve shared logical CPs
(six for LP2 and six for LP3) to be dispatched into six physical CPs. If all twelve logical CPs
have tasks to run, six of them have to wait. After the physical upgrade, up to seven shared
logical CPs can run at the same time.
Now let us consider the logical upgrades, assuming that all operating systems running in
these partitions have the capability of configuring processors online. Partition LP1, which has
two reserved CPs defined, can configure up to two more CPs online. In this example, LP1 is
CP0 CP1 CP2 CP3 Spare Spare Spare Spare CP4 CP5 CP6 Spare Spare Spare
Book 0 Book 1
Logical
CP0
DED
Logical
CP1
DED
Logical
CP2
DED
CP7 CP8
LP1
LP2
2084-B16
Model 309
Res
CP
Res
CP
LP3
CP0 CP1 CP2 CP3 Spare Spare Spare Spare CP4 CP5 CP6 Spare
Book 0 Book 1
Logical
CP0
DED
Logical
CP1
DED
Logical
CP2
DED
CP7 CP8
LP1
LP2
2084-B16
Model 311
Res
CP
LP3
CP9 CP10
Logical
CP3
DED
Logical
CP0
SHR
Logical
CP1
SHR
Logical
CP2
SHR
Res
CP
Res
CP
Logical
CP3
SHR
Logical
CP0
SHR
Logical
CP1
SHR
Logical
CP2
SHR
Res
CP
Res
CP
Logical
CP3
SHR
Logical
CP4
SHR
Logical
CP5
SHR
Logical
CP4
SHR
Logical
CP5
SHR
Logical
CP0
SHR
Logical
CP1
SHR
Logical
CP2
SHR
Res
CP
Logical
CP3
SHR
Logical
CP0
SHR
Logical
CP1
SHR
Logical
CP2
SHR
Res
CP
Res
CP
Logical
CP3
SHR
Logical
CP4
SHR
Logical
CP5
SHR
Logical
CP4
SHR
Logical
CP5
SHR
Logical
CP6
SHR